Its hard to tell someone when to disclose. A few things I have learned is one to disclose in a public place to ensure the safety of your friend. Another thing is your friend can bring up the topic of HIV and see the other persons reaction. Or your friend can wait it out until their comfortable enough to disclose but that can be dangerous if feelings get involved. The most importantly is that your friend is comfortable and safe when disclosing. Just continue to be supportive and encouraging.

Thanks